This present disclosure relates to a gas turbine engine, and more particularly to improvements in providing cooling air from a compressor section to a turbine section in a gas turbine engine.
Gas turbine engines are known and typically include a fan delivering air into a bypass duct as propulsion air. Further, the fan delivers air into a compressor section where it is compressed. The compressed air passes into a combustion section where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors driving them to rotate.
It is known to provide cooling air from the compressor to the turbine section to lower the operating temperatures in the turbine section and improve overall engine operation. Typically, air from the high compressor discharge has been tapped, passed through a heat exchanger, which may sit in the bypass duct and then delivered into the turbine section. The air from the downstream most end of the compressor section is at elevated temperatures.
Running the operating temperatures in the turbine section at high temperatures provides efficiency gains in the gas turbine engine; however, the high temperatures are exceeding material limits and are driving the need for improved cooling air. That is, conventional cooling air methods fail to provide cooling air at sufficient pressure to be introduced to the highest pressure places of the gas turbine engine and at cool enough temperature to reduce key component temperatures.